[DG] [DG11] Linear type 2 short or can I use a long with a 10 inch tiller arm

[Derek - Raymarine - Moderator]

Hi Simon,

Thank you for your enquiry

The T2 Longstroke will be fine on a 10" couple radius - given the displacement of the boat, although not important in your case, it should be noted that we use the actual boat displacement as a guide, not the design displacement, since the actual displacement can often be as much a 20% greater than the design displacement.

Using the 10" couple radius will in effect make the T2 Longstroke perform as a T2 Shortstroke and so should be fine for your vessel.

With regards to your 2nd question - you are correct, it has the same motor as the T2 Long stroke and so the same thrust, the difference is entirely due to the geometry of a shorter stroke and shorter tiller bar radius.

With regards to the mechanical rudder end stops, it is essential these are strong enough to stop the drive BEFORE it reaches it own limit of travel, this is clearly stated in the installation handbook.



The reason for this is that when the autopilot is not being used, the rudder must not rely on the drive unit limit of travel as a means of stopping the rudder moving hard over, for example when reversing the wheel can sometimes bang hardover and this shock load can cause damage to the drive unit unless the rudder is stopped by the mechanical endstops. The torque from the drive will be much less than the shock load force exerted by the sea in some situations.

Regards

Derek